Flexible Electrochromic Zn Mirrors Based on Zn/Viologen Hybrid Batteries

Abstract

Herein, we present a strategy for a switchable electrochromic zinc mirror/battery, which acts as a battery and a switchable electrochromic device via the electrodeposition and dissolution of Zn onto a transparent electrode. In this device, Zn and viologen constitute the anode and the cathode, respectively. Upon battery charging, Zn is electrodeposited onto the electrode to form a mirror while electric energy is stored as chemical energy. If the Zn mirror dissolves, the stored energy is released as electric energy. Compared with traditional electrochemical metallic mirrors, energy is sufficiently and sustainably utilized in this way. Also, a high reflectance of 84.9% and a specific capacity of 65.0 mAh g −1 are obtained for the Zn mirror, suggesting its excellent mirror performance and intrinsic energy storage properties. It is believed that this successful introduction of the battery concept to electrochemical metallic mirrors opens a wide avenue to drive its development toward a more imaginative and environmentally friendly future.

Biredox‐Ionic Anthraquinone‐Coupled Ethylviologen Composite Enables Reversible Multielectron Redox Chemistry for Li‐Organic Batteries

“…Synthesis of EV-Br 2 : The EV-Br 2 sample was synthesized according to the literature. [49] In a typical procedure, 4,4'-bipyridine (1.0 g, 6.4 mmol) was added dropwise to bromoethane (2.1 g, 19.2 mmol) in 20 mL of acetonitrile under argon atmosphere. The mixture was stirred at room temperature for 2 h and then heated at 60 °C for 12 h. After cooling, a yellow precipitate was obtained and separated by filtration.…”

Poly(ionic liquid)‐Based Energy and Electronic Devices

“…Lately, we synthesized an imidazolium‐based anion‐exchange membrane as a separator for flexible electrochromic Zn mirrors based on Zn/viologen hybrid batteries (Figure 6). [ 59 ] The Zn could be electrodeposited on the electrode to form a mirror upon battery charging, while the stored energy is released when the Zn mirror dissolves. The imidazolium‐ based anion‐exchange membrane was used to avoid the short circuits caused by the penetration of viologen cations in the device.…”

A Cathodic Electrochromic Material Based on Thick Perylene Bisimide Film with High Optical Contrast and High Stability

“…Electrochromic (EC) materials, with color changing reversibly under potential bias, have been widely applied in the fields of smart windows, [1][2][3][4] autodimming mirrors, 5 electronic papers, 6 EC display 7,8 and infrared or thermal modulation 9,10 due to their dynamic optical modulation and low energy cost. At present, EC materials can be divided into the following categories: (1) inorganic materials represented by tungsten trioxide, (2) metal chelates represented by phthalocyanine and bis-terpyridyl ruthenium, (3) organic small molecular materials represented by viologen, and (4) conducting polymers represented by polypyrroles, polyanilines, polythiophenes, and their derivates.…”